LU-6285 libcfs: get rid of deprecated cpumask function usage

LU-6285 libcfs: get rid of deprecated cpumask function usage

In current kernel cpus_* functions are deprecated, replace them
with cpumask_* functions instead.
Also get rid of most of NR_CPUS

Change-Id: I573faadb2f60cdfb523158d32427e9cb456a9456
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/13926
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>